py: Free non-interned strings in the parser when not needed.

mp_parse_node_free now frees the memory associated with non-interned
strings.  And the parser calls mp_parse_node_free when discarding a
non-used node (such as a doc string).

Also, the compiler now frees the parse tree explicitly just before it
exits (as opposed to relying on the caller to do this).

Addresses issue #708 as best we can.

1 files changed, 0 insertions, 1 deletions

diff --git a/stmhal/pyexec.c b/stmhal/pyexec.c
index cac6f0cf0..01c0173ef 100644
--- a/stmhal/pyexec.c
+++ b/stmhal/pyexec.c
@@ -71,7 +71,6 @@ bool parse_compile_execute(mp_lexer_t *lex, mp_parse_input_kind_t input_kind, bo
     mp_lexer_free(lex);
 
     mp_obj_t module_fun = mp_compile(pn, source_name, MP_EMIT_OPT_NONE, is_repl);
-    mp_parse_node_free(pn);
 
     if (module_fun == mp_const_none) {
         return false;